Lactose Intolerance Among Koreans Found to Be Less Than Half the Previously Believed Rate

by Choi Bongseok

Published 24 Apr.2026 13:38(KST)

[Image=Milk Industry Promotion Board / AI-generated image]

As interest in milk consumption and digestive responses grows, a new study has drawn attention by revealing that the actual prevalence rate of lactose intolerance is much lower than previously believed. According to a joint research team from Dankook University and Eulji University, which published a study entitled "Prevalence and Distribution of Lactose Intolerance Among Koreans," the prevalence rate of lactose intolerance among Koreans, based on gastrointestinal clinical symptom criteria, was found to be approximately 31.9%.

This figure is considerably different from the conventional belief that "three out of four Koreans suffer from lactose intolerance." That perception has been repeatedly mentioned on major domestic portals and online content, but the latest research confirms that the actual prevalence is lower than previously thought. The survey was conducted with a total of 623 people aged 14 to 59, and utilized questionnaires in three categories to thoroughly examine milk consumption patterns and symptoms related to lactose intolerance.

According to the survey results, 29.5% of all respondents experienced gastrointestinal symptoms within two hours after drinking milk. While 39.3% reported having experienced discomfort at least once after consuming milk, the proportion classified as actually having lactose intolerance was about 30%, after excluding cases where symptoms appeared only once or twice in a lifetime or were caused by drinking cold milk too quickly.

[Image=Milk Industry Promotion Board / AI generated image]

The main symptoms identified were diarrhea, abdominal pain, and abdominal bloating, with about 74% of those who experienced symptoms reporting onset within two hours of consuming dairy products. This aligns with the existing diagnostic criteria for lactose intolerance. However, in most cases, the symptoms were mild to moderate and did not significantly interfere with daily life.

By age group, there was a slight increase in the proportion of people experiencing recurrent or chronic symptoms as age increased. This phenomenon is interpreted as being related to decreased lactase activity after adulthood. However, there was no significant difference in the overall prevalence rate across all age groups from teens to those in their fifties, suggesting that aging itself does not greatly increase the likelihood of developing lactose intolerance.

The research team stated, "The positive rate for lactose intolerance based on clinical symptom criteria is 31.9%, which is different from the conventional belief, and in most cases, the symptoms are only mild." These findings suggest that a scientific approach-judging based on individual symptoms rather than vague aversion to milk consumption-is necessary.

Adjusting how milk is consumed can also be helpful. Instead of drinking a large amount at once, consuming smaller amounts over time or choosing warm milk over cold milk may reduce discomfort. Fermented dairy products such as cheese or yogurt are relatively easier to digest and can be used as alternative foods. This study highlights the gap between social perception and the actual prevalence of lactose intolerance, while emphasizing the importance of making rational, evidence-based decisions.